Rabbit corneas are perfused in the specular microscope with varying ophthalmic medications and chemicals. Corneal swelling rates are determined for experimental and control corneas. Corneas are submitted for scanning and transmission electron microscopy. Compounds being studied include carbonic anhydrase inhibitors, steroids, and free radicals. BIBLIOGRAPHIC REFERENCES: Hull, D.S., Bowman, K. and Green, K.: "Effect of Brinolase on Corneal Endothelium" Canadian Journal of Ophthalmology 11:82, 1976. Hull, D.S., Green, K. and Bowman, K.: "Dextran Uptake Into and Loss from Corneas Stored in Intermediate-Term Preservative" Investigative Ophthalmology 15:663, 1976.